Electro-optical single crystal element, method for the preparation thereof, and systems employing the same

ABSTRACT

The present invention relates to an Electro-Optical (E-O) crystal elements, their applications and the processes for the preparation thereof. More specifically, the present invention relates to the E-O crystal elements (which can be made from doped or un-doped PMN-PT, PIN-PMN-PT or PZN-PT ferroelectric crystals) showing super-high linear E-O coefficient y c , e.g., transverse effective linear E-O coefficient y T c more than 1100 pm/V and longitudinal effective linear E-O coefficient y l c up to 527 pm/V, which results in a very low half-wavelength voltage V t   x  below 200V and V t   x  below about 87V in a wide number of modulation, communication, laser, and industrial uses.

CROSS REFERENCE TO RELATED APPLICATIONS

This application relates to, and claims priority from U.S. Prov. No.61/686,350 filed Apr. 4, 2012, and U.S. Prov. Ser. No. 61/802,796 filedMar. 18, 2013, the entire contents of each of which is fullyincorporated herein by reference.

FIGURE SELECTED FOR PUBLICATION

FIG. 2A

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the new type Electro-Optical (E-O)crystal elements, its applications and the processes for the preparationthereof. More specifically, the present invention relates to an E-Ocrystal element showing super-high effective (transverse andlongitudinal) linear E-O coefficient and very low half-wave voltageV_(π) useful in a wide number of modulation, communication, laser, andelectro-optical industrial uses.

2. Description of the Related Art

Recently PMN-PT based ferroelectric relaxor crystals have been welldeveloped because of its super-high piezoelectric properties such aselectrical strains an order higher than conventional piezoelectricmaterials and the electro-mechanical coupling factor over 90%. Thesecrystals have been used for piezoelectric applications, especially foracoustic transduction devices, such as ultrasound imaging and sonartransducers. The very anisotropic piezoelectric characteristics of <011>poled PMN-PT and/or PZN-PT based crystals have been well documented.These can be noted in Applicant's prior publications, the entirecontents of which are incorporated herein fully by reference:

-   -   P. Han, W. L. Yan, J. Tian, X. L. Huang, and H. X. Pan. “Cut        directions for the optimization of piezoelectric coefficients of        lead magnesium niobate—lead titanate ferroelectric crystals”.        Discovery of d36 shear mode, Appl. Phys, Letter. 86, No. 1,        2466, (2005); and    -   P. Han, J. Tian, and W. Yan, “Bridgman growth and properties of        PMN-PT single crystals,” in Advanced dielectric, piezoelectric        and ferroelectric materials: Synthesis, characterization and        applications, Z. G. Ye, Ed., 1st Ed: Woodhead Publishing Ltd.,        2008, p. 600-632. (The summary of large-sized PMN-PT crystals        growth by modified Bridgman method and characterizations).        The linear E-O effects of <001> poled and <111> poled PMN-PT and        PZN-PT ferroelectric crystals above have been reported, but the        results were not encouraged or promoted as inoperative for        commercial uses. These results were noted in the publications        below, the entire contents of which are also incorporated herein        fully by reference.    -   Yu Lu, Z. Y. Cheng, S. E. Park, S, F Liu and Q. M. “Zhang”        linear Electro-Optic effect of 0.88Pb(Zn1/3Nb2/3)O3 single        crystal”, Jpn. J Appl. Phys Vol. 39 No. 1, January, 2000.    -   X. M. Wan, D. Y. Wang, X. Y. Zhao, Haosu Luo, H. L. W. Chan        and C. L. Choy. “Electro-Optic characterization of tetragonal        (1-x)Ob(Mg1/3Nb2/3)O3 single crystals by a method Senarmont        Setup” Slid state communications Vol. 134 547-551 (2005).    -   L. S. Kamzina, Ruan Wei, G. Li, J. Zeng and A. Ding.        “Electro-Optical properties of PMN-PT compounds: single crystals        and transparent ferroelectric ceramics”. Physics of solid state,        Vol. 52. No. 10 2142-2146 (2010). (Original Russian text).    -   Enwei Sun, Zhu Wang, Rui Zhang and Wenwu Cao. “Reduction of        electro-optic half-wave voltage of        0.93Pb(Zn1/3Nb2/3)3-0.07PbTiO3 single crystal through large        piezoelectric strain”. Optical Materials Vol. 33.m 549-552        (2011).

The major reason is the light scattering from multi-domain walls and theinstability of <111> poled single domain status and that all thereported works were limited in optical uniaxial crystals of the PMN-PTor PZN-PT based solid solutions.

ASPECTS AND SUMMARY OF THE INVENTION

The present invention relates to E-O crystal elements of ultra-higheffective E-O coefficient γ_(c) and very low half-wave voltage V_(π) inPMN-PT and PZN-PT based ferroelectric single crystal materials. Theinvention gives new E-O crystal elements and related E-O crystal deviceswith benefit merits including:

(1) superior E-O properties and extremely low half-wave voltage V_(π),

(2) broad operating temperature range from −30 C up to 110 C,

(3) the high reliability by the re-poling capability, and

(4) a cost effective preparation method.

The invention enables the commercially application of the invented E-Ocrystal elements in a variety of the E-O crystal devices as a newgeneration of E-O crystal elements. It is especially applicable to E-Oswitching, E-O phase modulation, E-O amplitude modulation, laser beammodulation and optical birefringence devices.

The present invention also relates to the new type Electro-Optical (E-O)crystal elements, its applications and the processes for the preparationthereof. More specifically, the present invention relates to an E-Ocrystal element showing high effective transverse and longitudinallinear E-O coefficient and very low half-wave voltage V_(π) useful in awide number of modulation, communication, laser, and industrial uses.

The present invention also relates to an Electro-Optical (E-O) crystalelement, (which can be made from doped or un-doped PMN-PT, PIN-PMN-PT orPZN-PT ferroelectric crystals) showing super-high linear E-O coefficientγ_(c), e.g., transverse effective linear E-O coefficient γ^(T) _(c) morethan 1100 pm/V and longitudinal effective linear E-O coefficient γ^(l)_(c) up to 527 pm/V, which results in a very low half-wavelength voltageV^(l) _(π) below 200V and V^(T) _(π) below 87V in a wide number ofmodulation, communication, laser, and industrial uses. The presentinvention also notes that the proposed crystal element is operative as ameans for providing the results therein, stated differently, theproposed crystal elements are means for providing a transverse effectivelinear E-O coefficient γ^(T) _(c) more than 1100 pm/V and longitudinaleffective linear E-O coefficient γ^(l) _(c) up to 527 pm/V, whichresults in a very low half-wavelength voltage V^(l) _(π) below 200V andV^(T) _(π) below 87V, in products, systems, and apparatus containing thesame following operative configuration.

The E-O single crystal materials can be selected from PMN-PT (LeadMagnesium Niobate-Lead Titanate) or PIN-PMN-PT (Lead Indium niobate-Leadmagnesium Niobate-Lead Titanate) or PZN-PT (Lead Zinc Niobate-LeadTitanate) or doped crystals above. The invention particularly relates toa repole-able design, i.e., applied electrical field parallel to thepoling direction <011> in the crystals. The E-O crystal elements show(1) the effective transverse linear E-O coefficient γ^(T) _(c) as highas the range of 350-1100 pm/V (operating temperature from −30 C to 85 C)and very low half-wavelength voltage V^(T) _(π) less than 45 V (l/d=1),and (2) the effective longitudinal linear E-O coefficient γ^(l) _(c) ashigh as in the range of 280˜800 pm/V (operating temperature from −30 Cto 110 C) with very low half-wave voltage V^(l) _(x) less than 300V, andpreferably less than about 200V, and more preferably less than about150V. The ultra-high effective E-O coefficient γ_(c) and very low V_(π)in additional to the nature of re-poling capability enable the inventedcrystal elements to be used in a variety of the E-O devices as a newgeneration of E-O crystal elements. It is especially applicable to, butnot limited to, E-O switching, E-O phase modulation, E-O amplitudemodulation, laser beam modulation and optical birefringence devices.

In one aspect of the present invention the following example wasprovided as a transverse mode E-O crystal element as recited in claim 4was tested in the configuration of transverse mode E-O amplitudemodulation as recited in claim 12 (see FIG. 4A). The crystal compositionis 67.5% PMN-32.5% PT, <011> poled to mm2 nano-domain symmetry. Theoptical beam wavelength is 633 nm. The results are repeatable, and:

-   -   γ^(T) _(c): 1160 pm/V at 80 C, 527 pm/V at 20 C, 436 pm/V at −8        C, and 395 pm/V at −21 C    -   V^(T) _(π): 87.5 V at 80 C, 87.5 V at 20 C, 119 V-8 C. The V^(T)        _(π) data were normalized to ratio l/d=1.

where

-   -   γ^(T) _(c): (Transverse effective E-O coefficient); V^(T)        _(π):Transverse mode half-wave voltage.

According to one aspect of the present invention, there is provided amethod of producing an electro-optical crystal element, comprising thesteps of preparing a ferroelectric crystal having a chemical compositionrepresented by one of the chemical formulas:

Pb(Mg_(1/3)Nb_(2/3))_(1-x)Ti_(x)O₃ where x is defined as 0.22 to0.38  (I)

or

Pb(Zn_(1/3)Nb_(2/3))_(1-y)TiO₃ where y is defined as 0.04 to 0.11,  (II)

-   -   -   wherein, all the crystal elements can be doped or co-doped            with Lanthanum (La) up to 6% (wt %), Antimony (Sb), Tantalum            (Ta) up to 8% (wt %), Indium (In) up to 31% (wt %),            Zirconium (Zr) up to 5% (wt %) and at least one rare earth            element from the group consisting of: Cerium (Ce), Erbium            (Er), Terbium (Tb), Scandium (Sc), and Neodymium (Nd), up to            8% (wt %),

    -   slicing the crystal element to (011) and forming wafers, and

    -   polarizing into a mm2-symmetric structure by poling the crystal        element in <011> direction under 2 times of coercive field        (E_(c)) in a temperature range below 95° C.

According to another aspect of the present invention, there is provideda method of producing an electro-optical crystal element, wherein: thestep of polarizing results in one of a single domain and amulti-nano-domain structure.

According to another aspect of the present invention, there is provideda method of producing an electro-optical crystal element, furthercomprising the steps of: conducting a dicing of the prepared crystalelement, and conducting a polishing and an optical finishing of thecrystal element, thereby forming the electro-optical crystal element.

According to another aspect of the present invention, there is provideda method of producing an electro-optical crystal element, wherein:further comprising the steps of: electroding the crystal element.

According to another aspect of the present invention, there is provideda method of producing an electro-optical crystal element, wherein:providing a transverse mode crystal element, and the transverse modecrystal element providing <011> polarization and giving the transverseeffective E-O coefficient γ^(T) _(c) more than 527 pm/V and half-wavevoltage V^(T) _(π) less than 87.5 V (l/d=1) at room temperature 20° C.

According to another aspect of the present invention, there is provideda method of producing an electro-optical crystal element, wherein:providing a longitudinal mode crystal element, coating a transparentelectrodes on the longitudinal mode crystal element, and thelongitudinal mode crystal element providing <011> polarization oflongitudinal effective E-O coefficient γ^(l) _(c) more than 427 pm/V andV^(l) _(π) less than 300 V at room temperature 20° C.

According to another aspect of the present invention, there is provideda method of producing an electro-optical crystal element, comprising thesteps of: preparing a ferroelectric crystal having a chemicalcomposition represented by the chemical formula:

y*[Pb(In_(1/2)Nb_(1/2))O₃]-(1-y)*[Pb(Mg_(1/3)Nb_(2/3))_(1-x)Ti_(x)O₃]  (III)

-   -   where x is defined as 0.0 to 0.35, y as 0.0 to 0.35 slicing the        crystal element to (011) wafers, and    -   polarizing into mm2 symmetric structure by poling the crystal        element in <011> direction under 2 times of coercive field        (E_(c)) in a temperature range below 95° C.

According to another aspect of the present invention, there is provideda method of producing an electro-optical crystal element, according toformula III, further comprising the steps of providing a transverse modecrystal element, and the transverse mode crystal element providing <011>polarization and giving the transverse effective E-O coefficient γ^(T)_(c) above 500 pm/V and half-wave voltage V^(T) _(π) less than 12 V(l/d=7) at room temperature 20° C.

According to another aspect of the present invention, there is provideda method of producing an electro-optical crystal element, furthercomprising the steps of providing a longitudinal mode crystal element,coating a transparent electrode on the longitudinal mode crystalelement, and the longitudinal mode crystal element providing <011>polarization of longitudinal effective E-O coefficient above 427 pm/Vand V^(l) _(π) less than 300 V at room temperature 20° C.

According to another aspect of the present invention, there is providedan electro-optical system, the system being one of an amplitudemodulator and a phase modulator, comprising: a longitudinal modeelectro-optical crystal element produced by a method according toformula III, and the longitudinal mode electro-optical crystal elementincluding means for providing <011> polarization of longitudinaleffective E-O coefficient γ^(l) _(c) above 427 pm/V and V^(l) _(π) lessthan 300 V at room temperature 20° C.

According to another aspect of the present invention, there is providedan electro-optical system, the system being one of an amplitudemodulator and a phase modulator, comprising: a transverse modeelectro-optical crystal element produced by a method according toformulas I or II, and the transverse mode electro-optical crystalelement including means for providing <011> polarization and giving thetransverse effective E-O coefficient γ^(T) _(c) above 500 pm/V andhalf-wave voltage V^(T) _(π) less than 87.5 V (l/d=1) at roomtemperature 20° C.

According to another aspect of the present invention, there is providedan electro-optical system, the system being one of an amplitudemodulator and a phase modulator, comprising: a transverse modeelectro-optical crystal element produced by a method acceding to formulaIII, and the transverse mode electro-optical crystal element includingmeans for providing <011> polarization and giving the transverseeffective E-O coefficient γ^(T) _(c) above 500 pm/V and half-wavevoltage V^(T) _(π) less than 12 V (l/d=7) at room temperature 20° C.

According to another aspect of the present invention, there is providedan electro-optical modulator system for laser beams, comprising: aMach-Zehnder-type interferometer modulator on an (011) surface of anoptical electrical crystal element, and the optical electrical crystalelement produced by a method according to one of formulas I, II, andIII.

The above and other optional and adaptive aspects, features andadvantages of the present invention will become apparent from thefollowing description read in conjunction with the accompanyingdrawings, in which like reference numerals designate the same elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the anisotropic surface of piezoelectric coefficient d₃₁ of<011> poled E-O crystal.

FIG. 1A is a 3D plot of the anisotropic surface of piezoelectriccoefficient d₃₁ for a <011> poled E-O crystal of FIG. 1.

FIG. 1B is a 2D plot of the X-Y cut section of the 3D plot in FIG. 1Anoting the unique anisotropic property-positive d₃₁ and negative d₃₂,whereas both d₃₁ and d₃₂ are negative for <001> poling and <111> poling.

FIG. 2A is a transverse mode E-O crystal element with <011>polarization.

FIG. 2B is a longitudinal mode E-O crystal element with <011>polarization.

FIG. 3 is an E-O crystal wafer, diced, polished, and optically finishedinto an E-O crystal element (cell), as noted.

FIG. 3A is a longitudinal mode E-O amplitude modulator system using<011> poled E-O crystal element as noted herein.

FIG. 3B is a longitudinal mode E-O phase modulator system using <011>poled E-O crystal element as noted herein.

FIG. 4 is an E-O crystal wafer, diced, polished, and optically finishedinto an E-O crystal element (cell), as noted.

FIG. 4A is a transverse mode E-O amplitude modulator using <011> poledE-O crystal element as noted herein.

FIG. 4B is a transverse mode E-O phase modulator using <011> poled E-Ocrystal element as noted herein.

FIG. 5 is an E-O crystal wafer, diced, polished, and optically finishedinto an E-O crystal element (cell), in transverse mode.

FIG. 5A is a traveling-wave E-O modulator using <011> poled E-O crystalelement of a transverse mode, for example for use in communicationsystems.

FIG. 6A is an exemplary E-O modulator for laser beams, schematic drawingalong a top view of a Mach-Zehnder interferometer modulator on (011)surface, with recombination with in-phase beams.

FIG. 6B is an exemplary E-O modulator for laser beams, schematic drawingalong a top view of a Mach-Zehnder interferometer modulator on (011)surface, with recombination with off-phase beams.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to aspects of the invention.Wherever possible, same or similar reference numerals are used in thedrawings and the description to refer to the same or like parts orsteps. The drawings are in simplified form and are not to precise scale.The word ‘couple’ and similar terms do not necessarily denote direct andimmediate connections, but also include connections through intermediateelements or devices. For purposes of convenience and clarity only,directional (up/down, etc.) or motional (forward/back, etc.) terms maybe used with respect to the drawings. These and similar directionalterms should not be construed to limit the scope in any manner. It willalso be understood that other embodiments may be utilized withoutdeparting from the scope of the present invention, and that the detaileddescription is not to be taken in a limiting sense, and that elementsmay be differently positioned, or otherwise noted as in the appendedclaims without requirements of the written description being requiredthereto.

Various operations may be described as multiple discrete operations inturn, in a manner that may be helpful in understanding embodiments ofthe present invention; however, the order of description should not beconstrued to imply that these operations are order dependent.

The present invention provides an Electro-Optical (E-O) crystal element,applications and the processes for the preparation thereof, includingthe use of the same in further systems, lasers, and modulators, as willbe discussed.

More specifically, the present invention relates to an E-O crystalelement showing high effective transverse and longitudinal linear E-Ocoefficient and very low half-wavelength voltage V_(π) useful in a widenumber of modulation, communication, laser, and industrial uses.

The ferroelectric single crystal materials can be PMN-PT (Lead MagnesiumNiobate-Lead Titanate) or PIN-PMN-PT (Lead Indium niobate-Lead magnesiumNiobate-Lead Titanate) or PZN-PT (Lead Zinc Niobate-Lead Titanate)and/or doped crystals above. The invention particularly relates to arepole-able design <011>-poled (cubic notation) ferroelectric crystalsmentioned above. The optical transmittance of the poled crystals istransparent from 0.41 μm continues into the IR region at least through 5μm without any noticeable absorption bands. The E-O crystals givesuper-high effective/apparent electro-optic coefficient γ_(c)/γ*_(c),and revy low half-wave voltage below 87 V. This <011> repole-ablecharacteristic is strategically important for the practical applicationsin terms of reliability and convenience for uses. Another merit of therepole-able configuration is the low cost for the fabrication of E-Ocrystal elements. We have discovered that, the <011>-poled E-O crystalelements show (1) the effective transverse linear E-O coefficient γ^(T)_(c) as high as the range of 350˜1100 pm/V (operating temperature from−30 C to 110 C) and very low half-wave voltage V^(T) _(π) less than 85 V(l/d=1) and less than 12V (l/d=7), and (2) the effective longitudinallinear E-O coefficient γ^(l) _(c) as high as in the range of 280˜800pm/V (operating temperature from −30 C to 110 C) with very low half-wavevoltage V^(l) _(π) less than 315V. The ultra-high effective E-Ocoefficient γ_(c) and very low V_(π) in additional to the nature ofre-poling capability enable the invented crystal elements to be used ina variety of the E-O devices as a new generation of E-O crystalelements. It is especially applicable to E-O switching, E-O phasemodulation, E-O amplitude modulation, laser beam modulation, tunablefilter and optical birefringence devices.

Referring now to FIGS. 1-1B, Applicant has noted the unique propertythat the <011> poled PMN-PT and/or PZN-PT based crystals show a mm2orthorhombic symmetry of physical properties and especially give apositive piezoelectric coefficient d₃₁ (+700 pC/N) and a negative d₃₂(−1600 pC/N) all while d₃₃ still about 1000 pC/N, noting the absolutedifference in coefficient is very large.

Referring further now to FIGS. 2A-6B, this invention is made based onour now-recognized concepts: (1) large electrical strain changes of theferroelectric crystals induce large changes of the respondent opticalindex, (2) the anisotropic of strain changes significantly impact on theoptical index changes of the crystals, particularly for an opticalbiaxial crystals of PMN-PT based solid solutions, (3) <011> poledcrystals having stable nano-multi-domain structure leading to less lightscattering by domain walls or single domain status if the crystalcomposition closed to the morphotropic phase boundary (MPB), and (4) abiaxial optical crystal is preferred as an incident polarized light tothe crystal should be divided into two components of polarized lightperpendicular each other. It is expected that higher anisotropicpiezoelectric response in the crystal offers more chances for higherlinear E-O responses. No reports have provided an E-O effect on biaxialoptical crystals of PMN-PT or PZN-PT based solid solutions. Thus, weselected from and focused at the <011> cut and poled crystals above withoptical bi-axes for the linear E-O effect.

Note: <001> poling results in 4 mm symmetric multi-domain structure andproperty and <111> poling results in 3 m symmetric single domain andproperty, both must be optical uniaxial, whereas the <011> poling mustresult in optical biaxial status this is a substantial difference thatmust be recognized and has not been in the art.

TABLE 1 gives a list of commercial E-O crystals Major tensors Apparentcontributing V^(T) _(π(l=d)) V^(l) _(π) λ Optical E-O Crystal γ_(c)* toγ_(c) V V Symmetry μm axis ADP 8.5 γ₆₃ 9,000 6800 42 m 0.546 uniaxial(NH₄ H₂PO₄) KDP 10.5 γ₆₃ 17,600 8800 42 m 0.546 uniaxial (KH₂PO₄) LiNO₃31 γ₃₃ 3,030 5,300  3 m 0.633 uniaxial BNN 350 γ₃₃ 1,570 1,100 mm2 0.633biaxial Ba₂N_(a)Nb_(S)O₁₅ KTP 35 γ₃₃ mm2 0.633 biaxial (KTiOPO₄) KNbO₃64 γ₃₃ mm2 0.633 biaxial γ_(c) Effective E-O coefficient, pm/V γ_(c)*Apparent E-O coefficient, pm/V, piezoelectric effect compensated γ_(c.)V^(l) _(π) Longitudinal half- wave voltage V^(T) _(π(l=d)) Transversehalf- wave voltage (normalized to l = d)

TABLE 2 Extremely low half-wave voltage V_(π) of E-O crystals of theinvention. Major tensors Apparent contributing V^(T) _(π(l=d)) V^(l)_(π) λ Optical E-O Crystal γ_(c)* to γ_(c) V V Symmetry μm axis PMN-PT*527-1,100 γ₁₃ γ₂₃ γ₃₃ 87 300 mm2 1.55 biaxial <011> poling PIN-PMN-PT*500-1,030 γ₁₃ γ₂₃ γ₃₃ 95 315 mm2 1.55 biaxial <011> poling *Thisinvention The E-O single crystal materials can be PMN-PT (Lead MagnesiumNiobate-Lead Titanate) or PIN-PMN-PT (Lead Indium niobate-Lead magnesiumNiobate-Lead Titanate) or PZN-PT (Lead Zinc Niobate-Lead Titanate)and/or doped crystals of the above.

Experimental Sample 1

A transverse mode E-O crystal element with composition: 67.5% PMN-32.5%PT single crystal element. The cut direction, poling direction andconfiguration of incident light and crystallographic orientation areshowing in FIG. 2A. The test results as follows:

Data Tested at Different Temperatures

−21° C. −8° C. 20° C. 80° C. γ^(T) _(c) 395 436 530 1160 V^(T) _(π) l/d= 1 119 87 37.5 γ^(T) _(c): effective transverse linear E-O coefficientV^(T) _(π): halfwave voltage Normalized to l/d = 1

Experimental Sample 2

A longitudinal mode E-O crystal element with composition: 67.5%PMN-32.5% PT single crystal element. The cut direction, poling directionand configuration of incident light and crystallographic orientation areshowing in FIG. 2B. The test results as follows: the effectivelongitudinal linear E-O coefficient γ^(l) _(c) as high as 450 pm/V at 20C with very low half-wave voltage V^(l) _(π) less than 300V.

Experimental Sample 3

A longitudinal mode E-O crystal element with composition: 24% PIN52.4%PMN-23.6% PT single crystal element. The cut direction, poling directionand configuration of incident light and crystallographic orientation areshowing in FIG. 3. The test results as follows: The effectivelongitudinal linear E-O coefficient γ^(l) _(c) as high as 500 pm/V at 20C with very low half-wave voltage V^(l) _(π) less than 315V.

Experimental Sample 4

A transverse mode E-O crystal element with composition: 24% PIN52.4%PMN-23.6% PT single crystal element. The cut direction, poling directionand configuration of incident light and crystallographic orientation areshowing in FIG. 4. The test results as follows: The effective transverselinear E-O coefficient γ^(T) _(c) over 527 pm/V at 20 C with very lowhalf-wave voltage V^(T) _(π) less than 95V.

Referring specifically now to FIG. 5A an electro optical system withtransverse mode crystal may contain an electro optical crystal spacingtransmission lines, for example in a communication system, havingmatched termination, as shown, and operatively linked with a modulationsignal source, as also shown. Additionally included is a polarizationfeature (here a quarter wave plate), and an output polarizer. Othersupportive structures will be understood by those of skill in therespective arts having studied the proposed invention. As a result, thepresent invention provides an electro optical system, for example, anoptical imaging system, a laser system, a communication system, orotherwise as will be understood by those of skill in the art havingstudied the proposed disclosure.

Additionally referring now to FIGS. 6A and 6B, it will be understoodthat those of skill in the art will note laser switching system foroptical fibers (fiber communications) electrodes and beam or channelwaveguides and switches (with appropriate losses) may be employed withthe present electro optical crystal element employed as a switch,coupling element, or other functional element in an a small crystalbetween either electrode, with the laser fiber linking to the smallcrystal, a laser system, or a communication system, or otherwise as willbe understood by those of skill in the art having studied the proposeddisclosure.

The present invention also provides the use of the disclosed E-Oelements in commercial E-O crystal element applications containing avariety of the E-O crystal devices as a new generation of E-O crystalelements. It is especially applicable to E-O switching systems andmethods, E-O phase modulation systems and methods, E-O amplitudemodulation systems and methods, laser beam modulation and opticalbirefringence devices and related systems and methods, and theaccompanying systems that include the same.

The novel features that are considered characteristic of the inventionare set forth with particularity in the appended claims. The inventionitself, however, both as to its structure and its operation togetherwith the additional object and advantages thereof will best beunderstood from the following description of the preferred embodiment ofthe present invention when read in conjunction with the accompanyingdrawings. Unless specifically noted, it is intended that the words andphrases in the specification and claims be given the ordinary andaccustomed meaning to those of ordinary skill in the applicable art orarts. If any other meaning is intended, the specification willspecifically state that a special meaning is being applied to a word orphrase.

Moreover, even if the provisions of 35 U.S.C. 112, paragraph 6, areinvoked to define the inventions, it is intended that the inventions notbe limited only to the specific structure, material or acts that aredescribed in the preferred embodiments, but in addition, include any andall structures, materials or acts that perform the claimed function,along with any and all known or later-developed equivalent structures,materials or acts for performing the claimed function.

In the claims, means- or step-plus-function clauses are intended tocover the structures described or suggested herein as performing therecited function and not only structural equivalents but also equivalentstructures. Thus, for example, although a nail, a screw, and a bolt maynot be structural equivalents in that a nail relies on friction betweena wooden part and a cylindrical surface, a screw's helical surfacepositively engages the wooden part, and a bolt's head and nut compressopposite sides of a wooden part, in the environment of fastening woodenparts, a nail, a screw, and a bolt may be readily understood by thoseskilled in the art as equivalent structures.

Having described at least one of the preferred embodiments of thepresent invention with reference to the accompanying drawings, it willbe apparent to those skills that the invention is not limited to thoseprecise embodiments, and that various modifications and variations canbe made in the presently disclosed system without departing from thescope or spirit of the invention. Thus, it is intended that the presentdisclosure cover modifications and variations of this disclosureprovided they come within the scope of the appended claims and theirequivalents.

1. A method of producing an electro-optical crystal element, comprisingthe steps of: preparing a ferroelectric crystal having a chemicalcomposition represented by one of the chemical formulas:Pb(Mg_(1/3)Nb_(2/3))_(1-x)Ti_(x)O₃ where x is defined as 0.22 to0.38  (I)orPb(Zn_(1/3)Nb_(2/3))_(1-y)TiO₃ where y is defined as 0.04 to 0.11,  (II)wherein, all said crystal elements can be doped or co-doped withLanthanum (La) up to 6% (wt %), Antimony (Sb), Tantalum (Ta) up to 8%(wt %), Indium (In) up to 31% (wt %), Zirconium (Zr) up to 5% (wt %) andat least one rare earth element from the group consisting of: Cerium(Ce), Erbium (Er), Terbium (Tb), Scandium (Sc), and Neodymium (Nd), upto 8% (wt %); slicing said crystal element to (011) and forming wafers;and polarizing into a mm2-symmetric structure by poling said crystalelement in <011> direction under 2 times of coercive field (E_(c)) in atemperature range below 95° C.
 2. The method of producing anelectro-optical crystal element, according to claim 1, wherein: saidstep of polarizing results in one of a single domain and amulti-nano-domain structure.
 3. The method of producing, according toclaim 1, further comprising the steps of: conducting a dicing of saidprepared crystal element; and conducting a polishing and an opticalfinishing of said crystal element, thereby forming said electro-opticalcrystal element.
 4. The method of producing, according to claim 3,further comprising the steps of: electroding said crystal element.
 5. Amethod of producing, according to claim 1, further comprising the stepsof: providing a transverse mode crystal element; and said transversemode crystal element providing <011> polarization and giving thetransverse effective E-O coefficient γ^(r) _(c) more than 527 pm/V andhalf-wave voltage V^(T) _(π) less than 87.5 V (l/d=1) at roomtemperature 20° C.
 6. A method of producing, according to claim 1,further comprising the steps of: providing a longitudinal mode crystalelement; coating a transparent electrodes on said longitudinal modecrystal element; and said longitudinal mode crystal element providing<011> polarization of longitudinal effective E-O coefficient γ^(l) _(c)more than 427 pm/V and V^(l) _(π) less than 300 V at room temperature20° C.
 7. A method of producing an electro-optical crystal element,comprising the steps of: preparing a ferroelectric crystal having achemical composition represented by the chemical formula:y*[Pb(In_(1/2)Nb_(1/2))O₃]-(1-y)*[Pb(Mg_(1/3)Nb_(2/3))_(1-x)Ti_(x)O₃]  (III)where x is defined as 0.0 to 0.35, y as 0.0 to 0.35 slicing said crystalelement to (011) wafers; and polarizing into mm2 symmetric structure bypoling said crystal element in <011> direction under 2 times of coercivefield (E_(c)) in a temperature range below 95° C.
 8. The method ofproducing an electro-optical crystal element, according to claim 7,wherein: said step of polarizing results in one of a single domain and amulti-nano-domain structure.
 9. The method of producing, according toclaim 7, further comprising the steps of: conducting a dicing of saidprepared crystal element; and conducting a polishing and an opticalfinishing of said crystal element, thereby forming said electro-opticalcrystal element.
 10. The method of producing, according to claim 9,further comprising the steps of: electroding said crystal element.
 11. Amethod of producing, according to claim 7, further comprising the stepsof: providing a transverse mode crystal element; and said transversemode crystal element providing <011> polarization and giving thetransverse effective E-O coefficient γ^(T) _(c) above 500 pm/V andhalf-wave voltage V^(T) _(π) less than 12 V (l/d=7) at room temperature20° C.
 12. A method of producing, according to claim 7, furthercomprising the steps of: providing a longitudinal mode crystal element;coating a transparent electrode on said longitudinal mode crystalelement; and said longitudinal mode crystal element providing <011>polarization of longitudinal effective E-O coefficient γ^(l) _(c) above427 pm/V and V^(l) _(π) less than 300 V at room temperature 20° C. 13.An electro-optical system, said system being one of an amplitudemodulator and a phase modulator, comprising: a longitudinal modeelectro-optical crystal element produced by a method acceding to claim7; and said longitudinal mode electro-optical crystal element includingmeans for providing <011> polarization of longitudinal effective E-Ocoefficient γ^(l) _(c) above 427 pm/V and V^(l) _(π) less than 300 V atroom temperature 20° C.
 14. An electro-optical system, said system beingone of an amplitude modulator and a phase modulator, comprising: atransverse mode electro-optical crystal element produced by a methodaccording to claim 1; and said transverse mode electro-optical crystalelement including means for providing <011> polarization and giving thetransverse effective E-O coefficient γ^(T) _(c) above 500 pm/V andhalf-wave voltage V^(T) _(π) less than 87.5 V (l/d=1) at roomtemperature 20° C.
 15. An electro-optical system, said system being oneof an amplitude modulator and a phase modulator, comprising: atransverse mode electro-optical crystal element produced by a methodacceding to claim 7; and said transverse mode electro-optical crystalelement including means for providing <011> polarization and giving thetransverse effective E-O coefficient γ^(T) _(π) above 500 pm/V andhalf-wave voltage V^(T) _(π) less than 12 V (l/d=7) at room temperature20° C.
 16. An electro-optical modulator system for laser beams,comprising: a Mach-Zehnder-type interferometer modulator on an (011)surface of an optical electrical crystal element; and said opticalelectrical crystal element produced by a method according to claim 1.17. An electro-optical modulator system for laser beams, comprising: aMach-Zehnder-type interferometer modulator on an (011) surface of anoptical electrical crystal element; and said optical electrical crystalelement produced by a method according to claim 7.